1. Field of the Invention
This invention relates to a method of wireless transmission of satellite positioning signal from an external antenna to an unexposed receiver, especially in mechanical vehicles. This invention relates further to a device, which uses the method of wireless transmission of a satellite positioning signal from an external antenna to an unexposed receiver, especially in mechanical vehicles, the device being provided with an active external antenna, comprising: the main antenna, a high-frequency amplifier, a transmission cable, a transmitting antenna, and a navigation device receiver.
2. Description of the Related Art
Due to very low strength of satellite signals, especially in the GPS system, a high level of interference within antennas, and the lack of full visibility of the satellites, in order to receive stronger and less noisy signal, external antennas are used. Such antennas are provided with an electrical connection to a receiver in the navigation device. However, an important limitation of this solution is the need to use non-standardized connections between the cables and the receiver of the navigation device. Moreover, it is not possible or difficult to connect certain navigation devices to an external antenna.
U.S. Pat. No. 6,222,501 describes an external antenna of a GPS receiver, which is connected with a laptop-type portable computer by means of a cable and a plug and which enables navigation using the display of the computer. A limitation of this solution lies in that the cable connection to the external antenna and the location of the antenna is in a place where satellites are visible.
Japanese Pat. JP 2006 174 505 describes a stationary device retransmitting the telecommunication signal from satellites to an area, which is shielded, e.g. by a building. This device operates as follows: the satellite antenna is located in a position, at which satellites are visible, and it sends the signals received from the satellites to a transmitter by means of a cable, and the transmitter resends the signal to the area, where the satellites are not visible.
U.S. Pat. No. 5,600,333 discloses a device for retransmitting radio or GSM phone signal, which consists of an antenna mounted to the windshield of a car and provided with a transmitter and to the receiver of the radio signal, which is mounted to the windshield within the car and is located just below the transmitter and which forwards the signal to a radio set by means of a cable.
Also known are devices for retransmission of GSM signal, which consist of an antenna mounted on the roof of a car and provided with an electric cable connection with a transmitter that is located within the car, and which forward the received signals to the phone antenna by means of induction.